If he agreed to marry rhea for a very good and valid reason (unlike arjun who simply married ovi because purvi told him to), then Ranbir couldn't be blamed, but I hope it is stopped before marriage to rhea is completed. There is a higher chance now too given that where for arjun-purvi nobody but ovi knew about their love, but for pranbir there are quite a few people who now know at least of ranbir's love for prachi.
Yeah which is why I suspect they might play bulbul-purab-aliya 2.0 here. Where purab agreed to marry Aliya even though he loved bulbul just for abhi's family and then he couldn't get through with it and left her at the altar. The next time,Aliya was pretending to be nice and changed and helping bulbul out and on purab and bulbul's wedding she attacked her and tried taking her place in the mandap,abhi suspected and stopped it.
Here so far, Ranbir is shown to take a stance for what he believes in so maybe they might recreate the same situation with different reactions.